The present invention relates to a semiconductor device. For example, the present invention relates to a semiconductor device in which a control signal supplied to a gate of a power device is controlled based on slew-rate control.
A motor that drives a vehicle or the like requires large electric power in order to obtain a large output. Therefore, an inverter circuit that drives such a high-power motor is formed by using power devices such as IGBTs (Insulated Gate Bipolar Transistors) that can withstand a high voltage and a large current. Further, a gate of such a power device has a large parasitic capacitance. Therefore, to operate a power device, a gate driver capable of driving the gate of the power device is used. Japanese Unexamined Patent Application Publication No. H10-70878 discloses an example of such a gate driver.
In the technique disclosed in Japanese Unexamined Patent Application Publication No. H10-70878, a gate drive circuit is formed by using an isolation circuit, a command selecting circuit, a plurality of transistors, gate resistors for an on-state, gate resistors for an off-state, and a gate power supply. An externally-commanded selection signal and a command signal are input to the command selecting circuit through the isolation circuit, and one of the gate resistors for an on-state and one of the gate resistors for an off-state are selected. Further, transistors corresponding to the selected gate resistor for an on-state and the gate resistor for an off-state are alternately turned on/off based on the command signal.